In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces.

BACKGROUND: Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation. METHODS: Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated. RESULTS: In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization. CONCLUSIONS: Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.

Low recurrence rate of a two-layered closure repair for primary and recurrent midline incisional hernia without mesh.

BACKGROUND: Incisional hernia is a serious complication after abdominal surgery and occurs in 11-23% of laparotomies. Repair can be done, for instance, with a direct suture technique, but recurrence rates are high. Recent literature advises the use of mesh repair. In contrast to this development, we studied the use of a direct suture repair in a separate layer technique. The objective of this retrospective observational study is to assess the outcomes (recurrences and complications) of a two-layered open closure repair for primary and recurrent midline incisional hernia without the use of mesh. METHODS: In an observational retrospective cohort study, we analysed the hospital and outpatient records of 77 consecutive patients who underwent surgery for a primary or recurrent incisional hernia between 1st May 2002 and 8th November 2006. The repair consisted of separate continuous suturing of the anterior and posterior fascia, including the rectus muscle, after extensive intra-abdominal adhesiolysis. RESULTS: Forty-one men (53.2%) and 36 women (46.8%) underwent surgery. Sixty-three operations (81.8%) were primary repairs and 14 (18.2%) were repairs for a recurrent incisional hernia. Of the 66 patients, on physical examination, three had a recurrence (4.5%) after an average follow-up of 2.6 years. The 30-day postoperative mortality was 1.1%. Wound infection was seen in five patients (6.5%). CONCLUSIONS: A two-layered suture repair for primary and recurrent incisional hernia repair without mesh with extensive adhesiolysis was associated with a recurrence rate comparable to mesh repair and had an acceptable complication rate.

Comparison of ultrasonography with computed tomography in the diagnosis of incisional hernias.

BACKGROUND: The objective of this study is to determine the reliability and validity of ultrasonography (US) in diagnosing incisional hernias in comparison with computed tomography (CT). The CT scans were assessed by two radiologists in order to estimate the inter-observer variation and twice by one radiologist to estimate the intra-observer variation. Patients were evaluated after reconstruction for an abdominal aortic aneurysm or an aortoiliac occlusion. METHODS: Patients with a midline incision after undergoing reconstruction of an abdominal aortic aneurysm or aortoiliac occlusion were examined by CT scanning and US. Two radiologists evaluated the CT scans independently. One radiologist examined the CT scans twice. Discrepancies between the CT observations were resolved in a common evaluation session between the two radiologists. RESULTS: After a mean follow-up of 3.4 years, 40 patients were imaged after a reconstructed abdominal aortic aneurysm (80% of the patients) or aortoiliac occlusion. The prevalence of incisional hernias was 24/40 = 60.0% with CT scanning as the diagnostic modality and 17/40 = 42.5% with US. The measure of agreement between CT scanning and US expressed as a Kappa statistic was 0.66 (95% confidence interval [CI] 0.45-0.88). The sensitivity of US examination when using CT as a comparison was 70.8%, the specificity was 100%, the predictive value of a positive US was 100%, and the predictive value of a negative US was 69.6%. The likelihood ratio of a positive US was infinite and that of a negative US was 0.29. The inter- and intra-observer Kappa statistics were 0.74 (CI 0.54-0.95) and 0.80 (CI 0.62-0.99), respectively. CONCLUSIONS: US imaging has a moderate sensitivity and negative predictive value, and a very good specificity and positive predictive value. Consistency of diagnosis, as determined by calculating the inter- and intra-observer Kappa statistics, was good. The incidence of incisional hernias is high after aortic reconstructions.

Evaluation of acellular dermis for closure of abdominal wall defects in a rat model.

BACKGROUND: Abdominal wall repair can be performed with synthetic or biological materials. Biological materials may reduce the risk of infections and fibrosis. The aim of this study was to evaluate two acellular human dermis products. MATERIALS AND METHODS: A rat model was used to compare the two materials. One was prepared using low concentrations of NaOH; the other material was SureDerm, which is commercially available. Full thickness defects were prepared in the abdominal wall and closed with the materials. Rats were sacrificed at 1 or 4 months after operation and the numbers of adhesions to the bowels were scored. Samples were taken for histological analysis and to measure the breaking strength. RESULTS: In both groups a good functional integration of the implants with the abdominal wall was observed. There was no adhesion formation with the bowels in the group with the NaOH prototype. In the SureDerm group, 4 out of 7 rats showed only small adhesions at 4 months after operation. Breaking strength of the healed tissue was significantly higher in the NaOH prototype group at 4 months after operation (p < 0.0026). CONCLUSIONS: The results indicate that both human acellular dermis products may be used in clinical trials for closure of abdominal wall defects.

Endoscopic versus transaxillary thoracic sympathectomy for primary axillary and palmar hyperhidrosis and/or facial blushing: 5-year-experience.

Thoracic sympathectomy is effective in the permanent cure of primary axillary and palmar hyperhidrosis and facial blushing, which can be so troublesome for patients that their social and professional relations can be affected. Between October 1988 and April 1994, a total of 50 thoracic sympathectomies (10 surgical and 40 endoscopic) were performed on 5 and 23 patients, respectively. The operations were performed unilaterally, followed by the contralateral intervention after a period of 6-8 weeks. The thoracic ganglia T2-T5 were resected for hyperhidrosis. If the patient suffered from blushing, the lower 1/3 of the stellate ganglion was also resected. Postoperatively, all the operated limbs were warm and dry. In the group of patients who were operated bilaterally, only one had persistent facial blushing. The efficacy for blushing in this series was therefore 93.3%. The late relapse rate of sympathetic activity was 14.3%. Compensatory sweating was seen in 67%, gustatory sweating in 37.5% and phantom sweating in 29% of the patients. None of them considered these side effects to be troublesome. Although there is no difference between transaxillary thoracic sympathectomy and the endoscopic intervention in terms of efficacy, the latter is associated with less postoperative pain, shorter hospital stay and a rapid recovery. The thoracic sympathectomy is the treatment of choice for primary hyperhidrosis and excessive facial blushing.

The distribution of peripheral vascular disease in a Dutch Caucasian population: comparison of type II diabetic and non-diabetic subjects.

OBJECTIVES: To study the distribution of peripheral vascular disease and the relationship to diabetes. DESIGN: Prospective population based study of Dutch caucasian inhabitants. METHODS: From a total of 10,500 subjects aged between 50 and 75 years, 2484 Caucasian inhabitants were screened with respect to their glucose tolerance. Subjects using oral antidiabetic agents or insulin were classified directly as having diabetes mellitus. The other participants were screened using two oral glucose tolerance tests and classified using WHO criteria. A group of 173 people with diabetes and a representative age/sex stratified sample of 288 non-diabetic subjects were seen in the vascular laboratory. Carotid artery disease was investigated with Duplex scanning, arm and leg artery obstructions with real time frequency analysis of continuous wave Doppler signals and indirect blood pressure measurements. RESULTS: Comparing diabetic with non-diabetic subjects, we found significantly more obstructions of the carotid arteries (8.7 vs 2.8%), arm arteries (2.3 vs 0%), as well as leg arteries (31.8 vs. 18.4%). The same holds if only the crural artery obstructions were compared (23.7 vs 16.0%). Two of the four diabetic subjects with arm artery obstructions had retrograde vertebral flow, three of them had carotid artery obstructions as well, and three also had leg artery obstructions. More than half of the subjects with a carotid artery obstruction, also had leg artery obstructions. CONCLUSIONS: Peripheral vascular disease is common in diabetes, but most are asymptomatic.

[Ascending phlebothrombosis]. / Ascenderende flebotrombose.

Ascending phlebothrombosis of the lower extremities can have serious consequences if not identified at an early stage. In the Academic Hospital of the Free University, Amsterdam, 18 patients with this disease were seen in the period 1980-1991. Treatment should be aimed at preventing progression of the disease to the deep venous system. This may necessitate ligation and dissection of the V. saphena magna in the groin. Usually conservative treatment will do, provided regular follow-up is performed to see whether progression has taken place to the hiatus saphenus or the popliteal fossa. As the disease has usually progressed further than the clinical signs indicate, duplex scanning should be used in case of doubt. Progression to the deep system should immediately be treated surgically.

Two sisters with coeliac disease and jejunal cancer: just a coincidence?

Two sisters with asymptomatic coeliac disease are described; they both developed a primary jejunal cancer at the same age. While screening the family, a third sister was found to have coeliac disease, but without detectable cancer in the small intestine or stomach. These findings suggest an increased susceptibility in this family for carcinoma developing secondary to asymptomatic coeliac disease. We conclude that the finding in a patient of the combination of coeliac disease and malignancy in the digestive tract is sufficient reason to investigate the first-degree relatives with regard to the presence of coeliac disease and a secondary carcinoma.